What are the minimum allowable slopes for concrete flatwork to ensure proper drainage?

The minimum allowable slope for concrete flatwork to ensure proper drainage is 1/8" per foot. This slope is essential because it helps direct water away from the surface, preventing puddles and potential water accumulation that can lead to erosion, freezing, and damage to the concrete.

Having a slope of at least 1/8" per foot is a common practice in concrete flatwork, as it strikes a balance between effective drainage and usability. Slope steeper than this may cause problems for users, such as difficulty walking or maneuvering equipment.

While options like 1/16" per foot might not provide adequate drainage over larger areas, a slope less than 1/8" risks water pooling on the surface, which can compromise both the integrity of the concrete and safety for pedestrians or vehicles. Therefore, the 1/8" per foot recommendation is widely accepted in the industry.